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What does "nullable" mean in programming?
nullable is one of the most common terms in software development. This guide explains what it means, how it is used in practice, and why it matters, with real examples from the developer world.
Definition
A type that can hold either a valid value or null. In TypeScript you express a nullable type as T | null. Explicitly marking a type as nullable makes it clear when the absence of a value is allowed.
Example
"let username: string | null = null; // nullable string"
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